code: def render_ddl_sql_expr(
      self, expr: ClauseElement, is_server_default: bool = False, **kw
  ) -> str:
      # SQLite expression defaults require parenthesis when sent
      # as DDL
      str_expr = super().render_ddl_sql_expr(
          expr, is_server_default=is_server_default, **kw
      )
  
      if (
          is_server_default
          and self._guess_if_default_is_unparenthesized_sql_expr(
              str_expr
          )
      ):
          str_expr = "(%s)" % (str_expr,)
      return str_expr
  
imports: from __future__ import annotations
  import re
  from typing import Any
  from typing import Dict
  from typing import Optional
  from typing import TYPE_CHECKING
  from typing import Union
  from sqlalchemy import cast
  from sqlalchemy import JSON
  from sqlalchemy import schema
  from sqlalchemy import sql
  from .base import alter_table
  from .base import format_table_name
  from .base import RenameTable
  from .impl import DefaultImpl
  from ..None import util
  from ..util.sqla_compat import compiles
label_desc: Use image node_id 7 for calling the SQLiteImpl obj's underlying member method code with example usage: obj.render_ddl_sql_expr(expr, is_server_default) and returns: str_expr